This invention relates to apparatus for projecting in free flight a succession of discrete objects with a closely controlled trajectory and frequency; in particular it relates to a device for accepting a spaced feed of discrete objects, for example nuts and bolts, and projecting them with a predetermined velocity and a predetermined frequency.
Apparatus has been disclosed ( e.g. GB 2 201 648 ) for feeding objects accurately and with controlled frequency, but though it can be highly effective this apparatus requires a large number of components and can therefore be expensive.
Less accurate apparatus for feeding a succession of objects is disclosed in GB 2167029, in which the feeder has a circulating conveyor belt engaging a roll in such a way that the part of the belt immediately downstream of the roll extends in the direction of rotation. The roll has a circumferential channel into which successive objects are fed ensuring that the objects are travelling at and are released with a speed close to the circumferential speed of the roll and the belt.
This apparatus has the disadvantage that in order to operate smoothly, the belt and the base of the channel need to be of highly compressible material, which is found to release the objects with some perturbation.
It is desirable to provide apparatus that can project objects in spaced succession with an accurately controlled trajectory and frequency that does not need a large number of components.